This invention relates to valves and, more particularly, to an axial flow valve that utilizes a flexible tubular throttling member. The use of a flexible member to act as a throttling element in a valve is known. However, in many prior art valves the flexible member is subject to "tension set" that adversely effects the reliability and/or useful life of the valve. Accordingly, one object of this invention is to provide a valve having a flexible member therein that is not adversely effected by tension set.
For obvious reasons, it is desirable that valves be designed such that they can be economically manufactured. Accordingly, another object of this invention is a provide a valve having a flexible member therein that has a simplified design that enables it to be economically manufactured.
For overall general utility in various environments and systems, it is desirable that a valve be capable of being manufactured in various sizes. Accordingly, yet another object of this invention is to provide a valve that can readily be manufactured in various sizes.
It is a further object of this invention to provide a valve wherein shut-off of gaseous flow is bubble tight and shut-off of liquid flow is leak tight.
It is a still further object of this invention to provide an improved valve design wherein the cracking differential pressure is uniform between valves.